1. Field of the Invention
The present invention relates to a substrate processing method and substrate processing apparatus for processing substrates.
2. Related Background Art
In photolithography processing for, e.g., a semiconductor wafer (hereinafter called xe2x80x9ca waferxe2x80x9d), a resist is applied to the wafer, and a pattern is exposed and developed. Then, the resist is removed from the wafer.
A cleaning equipment is used in such removal of the resist. In the conventional cleaning equipment, a wafer is immersed in a cleaning tank loaded with a chemical liquid which is called SMP (a mixed liquid of H2SO4/H2O2) to release the resist. On the other hand, recently it is required from the ecological viewpoint that the resist is removed by using a solution with ozone (O3) solved in, which is easy to waste. In such cleaning, the so-called dip-type, in which a wafer is immersed in a cleaning tank loaded with a solution with ozone solved in, is used to oxidize the resist with oxygen radicals in the solution to decompose the resist to carbon dioxide, water, etc.
The solution is produced by bubbling a high concentration of ozone gas into pure water to solve the ozone in the pure water, and the thus produced solution is loaded in a cleaning tank. Meanwhile the ozone in the solution is decomposed to decrease the ozone concentration of the solution, which often makes it impossible to sufficiently remove the resist. Furthermore, with a wafer immersed in the solution, while the ozone is reacting with the resist and is continuously being decomposed, ozone supply to the resist surface is insufficient, which makes a reaction rate low.
Then, a cleaning equipment in which ozone gas and steam are used to utilize ozone for the processing for removing a resist from a wafer is anew proposed in place of the cleaning equipment of the dip-type, in which a wafer is immersed in the solution. In such cleaning equipment, ozone gas is applied to wafers loaded in a tightly closed processing vessel. For processing using ozone, which is a harmful substance to the human body, etc., it is required that various accident preventive means and safety means are used.
Thus, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus which can prevent accidents in advance, specifically, can ensure safety even if the apparatus should be instantaneously stopped due to power failures or others, or processing gas leakage should take place.
An object of the present invention is to provide a substrate processing method and a substrate processing apparatus which can prevent accidents in advance, specifically, can ensure safety even if the apparatus should be instantaneously stopped due to power failures or others, or processing gas leakage should take place.
To solve the above-described problems, a first invention of the present application provides a substrate processing method in which a substrate is processed by feeding a processing gas to the substrate loaded in a processing vessel while an interior atmosphere in the processing vessel is being exhausted to be subjected to a post-treatment, the processing gas being fed under a condition that the processing vessel is tightly closed, and the post-treatment of the exhausted interior atmosphere is normally carried out.
In a first substrate processing method according to the present invention, ozone gas, for example, is suitably used as the processing gas. According to the first substrate processing method of the present invention, the processing gas is fed to substrates loaded in the tightly closed vessel, and the substrates are suitably processed in the processing vessel by using the processing gas. On the other hand, an interior atmosphere in the processing vessel is exhausted to thereby exhaust the processing gas out of the processing vessel. The exhausted processing gas is post-treated. In the post-treatment, when a processing gas, e.g., ozone gas, contains a substance (ozone) which is harmful to the human body, the harmful substance is removed, making the processing gas harmless to be exhausted for safety to, e.g., an exhaust system of a plant. A processing gas can be, other than ozone gas, e.g., chlorine gas, fluoride gas, hydrogen gas, chlorine gas, fluoride gas, hydrogen gas, etc. containing various radicals in advance.
Here, when a processing gas is fed before the processing vessel is tightly closed, the processing gas disperses around. When the post-treatment is abnormal, there is a risk that the processing gas may be discharged as it is to an exhaust system of a plant. However, according to the present invention, the processing gas is fed under conditions that the processing vessel is tightly closed, and that the exhausted interior atmosphere is normally post-treated, and unless both conditions are satisfied, the processing gas is not fed, whereby the dispersion and the untreated drain of the processing gas can be prevented. Especially in a case that the processing gas contains ozone gas, which is harmful, accidents to the human body due to, e.g., the harmful substance can be precluded.
In a second substrate processing method according to the present invention, it is possible that when the processing of the substrate is interrupted, the interior atmosphere of the processing vessel is forcedly exhausted. When the processing is interrupted by, e.g., a power failure, an earthquake or others, the interior atmosphere in the processing vessel is forcedly exhausted to expel the processing gas from the interior of the processing vessel. Then, when the processing is resumed, often operators of the plant, for example, open the processing vessel to check interior states of the processing vessel. If the processing vessel is opened with the processing gas remaining therein, the processing gas may disperse. However, the thus forced-exhaust of the processing gas can prevent such dispersion of the processing gas. Especially when the processing gas is ozone gas, the forced exhaust of the processing gas can prevent such accident for safety.
In a third substrate processing method according to the present invention, it is possible that when the processing gas leaks around the processing vessel, the interior atmosphere of the processing vessel is forcedly exhausted while the feed of the processing gas is paused. According to the third substrate processing method, when the gas leakage has occurred, immediately the interior atmosphere is forcedly exhausted while the feed of the processing gas is stopped, whereby no more gas leakage can occur, and the damage can be minimized.
A fourth substrate processing method according to the present invention which a substrate is processed by feeding a processing gas to the substrate loaded in a processing vessel while an interior atmosphere in the processing vessel is being exhausted to be post-treated, when the processing gas leaks around the processing vessel, the interior atmosphere of the processing vessel is forcedly exhausted while the feed of the processing gas is paused.
According to the fourth substrate processing method of the present invention, as in the first substrate processing method, ozone gas, for example, can be suitably used as the processing gas. In the fourth substrate processing method according to the present invention, as in the first substrate processing method, the processing gas is fed into the processing vessel, and the substrates are suitably processed. On the other hand, the processing gas is exhausted out of the processing vessel, then is post-treated to be made harmless to be exhausted for safety to, e.g., an exhaust system of a plant. Here, when the processing gas leaks through, e.g., a gap of the processing vessel, at the time of the gas leakage, immediately the interior atmosphere is forcedly exhausted while the feed of the processing gas is paused. Then, the processing gas is prevented from leaking from the processing vessel. Thus, the leakage of the processing gas can be minimized for safety.
According to a fifth substrate processing method of the present invention, it is preferable that in the fourth substrate processing method, the processing gas leaks around the processing vessel, the peripheral atmosphere of the processing vessel is exhausted, and the exhausted processing gas is post-treated. Thus, even when the processing gas leaks around the processing vessel, the peripheral processing gas is made harmless to be exhausted for safety to, e.g., an exhaust system of a plant.
According to a sixth substrate processing method of the present invention, it is possible that when the processing gas leaks, the peripheral atmosphere of the processing vessel is forcedly exhausted. Thus, the processing gas is prevented without failure from dispersing beyond the periphery of the processing vessel in a large area. Accordingly, even when the processing gas leaks, safely no accident occurs.
According to a seventh substrate processing method of the present invention, it is preferable that the interior of the processing vessel is opened after a concentration of the processing gas in the processing vessel has been detected, and it has been confirmed that a detected processing gas concentration is below a prescribed value. A prescribed value is set to be a concentration which is harmless to the human body, etc. The processing vessel is opened after safety is thus confirmed, whereby accident can be precluded.
According to an eighth substrate processing method of the present invention, it is possible that the interior of the processing vessel is opened by pausing the feed of the processing gas, and then exhausting the interior atmosphere of the processing vessel for at least a prescribed period of time. In the eighth substrate processing method, the interior atmosphere in the processing vessel is exhausted for a prescribed period of time, whereby a processing gas concentration in the processing vessel can be below a prescribed value. Thus, accidents can be precluded for safety.
According to a ninth substrate processing method of the present invention, it is preferable that when the feed of the processing gas is paused, and the interior atmosphere of the processing vessel is exhausted, a negative pressure atmosphere is established in the processing vessel. A positive pressure atmosphere is established in the processing vessel when the interior atmosphere is exhausted, there is a risk that the processing gas may leak around. However, in the ninth substrate processing method, a negative pressure atmosphere is established in the processing vessel, whereby the leakage of the processing gas can be prevented.
According to a tenth substrate processing method of the present invention, when post-treatment is not carried out normally, the interior atmosphere of the processing vessel is forcedly exhausted while the feed of the processing gas is paused.
A first substrate processing apparatus according to the present invention in which a processing gas is fed by processing gas supply nozzle to a substrate loaded in a processing vessel while an interior atmosphere of the processing vessel is being exhausted through an interior atmosphere exhaust pipe line to be post-treated by a post-treatment mechanism, the apparatus comprising an opening/closing member for opening/closing a load/unload opening of the processing vessel; and controller for controlling feed of the processing gas by the processing gas supply nozzle, based on a detected signal outputted by opening/closure detector for detecting opening/closure of the opening/closing member, and a detected signal outputted by operation detector for detecting an operational state of the post-treatment-mechanism.
In the first substrate processing apparatus of the present invention, the processing gas is suitably, e.g., ozone gas or others. According to the first substrate processing apparatus, the opening/closure member is opened to load substrates into the processing vessel, and then the opening/closure member is closed to tightly close the processing vessel. Then, the processing gas is fed into the processing vessel by the processing gas supply nozzle to suitably process the substrate. On the other hand, the interior atmosphere in the processing vessel is exhausted through the interior atmosphere exhaust pipe line to thereby exhaust the processing gas out of the interior of the processing vessel. The exhausted processing gas is post-treated by the post-treatment mechanism. In a case of, e.g., ozone gas containing ozone, which is harmful to the human body, the post-treatment mechanism uses a mechanism, such as the ozone killer, which removes a harmful substance (ozone). Then, in the post-treatment, the harmful substance is removed to make the processing gas harmless enough to be safely exhausted to, e.g., an exhaust system of a plant.
The controller permits the processing gas supply nozzle to feed the processing gas when the controller confirms that the opening/closure member is closed, based on a detected signal outputted by the opening/closure detector, and judges that the post-treatment mechanism is normally operable, based on a detected signal outputted by the operation detector. When the opening/closure member is opened, or the post-treatment mechanism is abnormal, the controller interrupts the supply of the processing gas by the processing gas supply nozzle, Thus, the first substrate processing apparatus of the present invention can preferably carry out the first substrate processing method of the present invention.
According to a second substrate processing apparatus of the present invention, it is preferable that in the first substrate processing apparatus of the present invention, the interior atmosphere exhaust pipe line comprises an ejector for forcedly exhausting the interior atmosphere of the processing vessel. In the second substrate processing apparatus, the ejector forcedly exhausts the interior atmosphere when, for example, the processing of the substrates is interrupted. Thus, the second substrate processing apparatus of the present invention can preferably carry out the second substrate processing method of the present invention.
According to a third substrate processing apparatus of the present invention, it is preferable that there are provided peripheral concentration sensor for detecting a processing gas concentration in a peripheral atmosphere of the processing vessel; a second ejector for forcedly exhausting the peripheral atmosphere of the processing vessel; and controller for controlling, based on a detected signal outputted by the peripheral concentration sensor, the forced exhaust by the ejector for forcedly exhausting the interior atmosphere of the processing vessel and the feed of the processing gas by the processing gas supply nozzle. In the third substrate processing apparatus, the controller operates the ejector and interrupts the supply of the processing gas by the processing gas supply nozzle when the controller detects leakage of the processing gas into the peripheral atmosphere of the processing vessel. Thus, the third substrate processing apparatus of the present invention can preferably carry out the third substrate processing method of the present invention.
According to a fourth substrate processing apparatus of the present invention, it is possible that there is provided controller for controlling the forced exhaust of the peripheral atmosphere by the second ejector, based on a detected signal outputted by the peripheral concentration sensor. In the fourth substrate processing apparatus, the controller operates the ejector when the controller detects leakage of the processing gas into the peripheral atmosphere of the processing vessel. Thus, the fourth substrate processing apparatus of the present invention can preferably carry out the sixth substrate processing method of the present invention.
A fifth substrate processing apparatus of the present invention in which a processing gas is fed by processing gas supply nozzle to a substrate loaded in a processing vessel while an interior atmosphere of the processing vessel is being exhausted through an interior atmosphere exhaust pipe line to be post-treated by a post-treatment mechanism, the apparatus comprising an opening/closing member for opening/closing a load/unload opening of the processing vessel; peripheral concentration sensor for detecting a processing gas concentration in the peripheral atmosphere of the processing vessel; a peripheral exhaust pipe line connected to a case for exhausting the peripheral atmosphere of the processing vessel; and controller for controlling, based on a detected signal outputted by the peripheral concentration sensor, the exhaust by the interior atmosphere exhaust pipe line and the feed of the processing gas by the processing gas supply nozzle.
In the fifth substrate processing apparatus of the present invention, as in the first substrate processing apparatus of the present invention, ozone gas, for example, is suitably used as the processing gas. According to the fifth substrate processing apparatus, as in the first substrate processing apparatus of the present invention, substrates are loaded in the processing vessel, and then the processing gas is fed into the processing vessel by the processing gas supply nozzle to suitably process the substrates. On the other hand, the processing gas is exhausted out of the processing vessel through the interior atmosphere exhaust pipe line. The exhausted processing gas is post-treated by the post-treatment mechanism and makes the exhaust processing gas harmless to be exhausted for safety to, e.g., an exhaust system of a plant. Here, when the controller detects, based on a detected signal, leakage of the processing gas into the peripheral atmosphere of the processing vessel, the controller enhances, if necessary, the operation of the interior atmosphere exhaust pipe line to thereby increase an exhaust rate of the interior atmosphere while interrupting the supply of the processing gas by the processing gas supply nozzle. Thus, the fifth substrate processing apparatus of the present invention can preferably carry out the fourth substrate processing method of the present invention.
In a sixth substrate processing apparatus of the present invention, when the concentration sensor has an abnormality, the controller pauses the feed of the processing gas while controlling the ejector to operate.
In a seventh substrate processing apparatus of the present invention, it is preferable that in the fifth substrate processing apparatus of the present invention, comprising controller for controlling the exhaust by the peripheral exhaust pipe line and the case, based on a detected signal outputted by the peripheral concentration sensor. Thus, the seventh substrate processing apparatus of the present invention can preferably carry out the sixth substrate processing method of the present invention.
According to a eighth substrate processing apparatus of the present invention, it is preferable that there are provided interior concentration sensor for detecting a processing gas concentration in the processing vessel; and controller for controlling the opening/closure of the opening/closing member, based on a detected signal outputted by the interior concentration sensor. In the eighth substrate processing apparatus, when the controller judges, after the supply of the processing gas is stopped, that a processing gas concentration in the processing vessel is below a prescribed value which is harmless to the human body, etc., based on a detected signal outputted by the interior concentration detector, the controller opens the opening/closure member. Thus, the eighth substrate processing apparatus of the present invention can preferably carry out the seventh substrate processing method of the present invention.
According to an ninth substrate processing apparatus of the present invention, it is possible that there is provided air supply nozzle for feeding air in the processing vessel. In the eighth substrate processing apparatus, when the interior atmosphere of the processing vessel is exhausted, air is fed by the air supply nozzle to thereby extrude the processing gas out of the processing vessel. An air supply rate is set to be lower than an exhaust rate of the interior atmosphere. When air is fed at a higher supply rate than an exhaust rate for the interior atmosphere, a positive pressure atmosphere is established in the processing vessel. In a positive pressure atmosphere, there is a risk that the processing gas may leak out of the processing vessel. An air supply rate is made thus lower, whereby the interior of the processing vessel is maintained in a negative pressure atmosphere to thereby prevent leakage of the processing gas and also realize quicker exhaust.